title: Recombinational reassortment among opa genes from ET-37 complex Neisseria meningitidis isolates of diverse geographical origins.
abstract: Opacity (Opa) proteins are a family of antigenically variable outer-membrane proteins of Neisseria meningitidis. ET-37 complex meningococci, defined by multilocus enzyme electrophoresis, have been isolated on different continents. Twenty-six different Opa proteins have been observed within strains of the ET-37 complex isolated between the 1960s and the 1980s, although individual strains have only four opa genes per chromosome. In this work the opa genes of four closely related ET-37 complex N. meningitidis strains recently isolated from Mali, West Africa were characterized and compared with the opa genes of strain FAM18, an ET-37 complex isolate from the USA. DNA sequence analysis and Southern blot experiments indicated that recombinational reassortment, including gene duplication and import by horizontal genetic exchange, has occurred in the opa genes within the ET-37 complex, resulting in two partially different Opa repertoires being present in FAM18 and the Mali isolates. Using synthetic peptides derived from the hypervariable (HV) regions of opa genes, the epitopes for nine mAbs were mapped. These bacteria, isolated on different continents, contain both shared and unique opa HV regions encoding epitopes recognized by mAbs and show evidence of recombinational reassortment of the HV regions.
authors.affiliation: Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: Marcia M
authors.initials: MM
authors.lastname: Hobbs
authors.affiliation: Max Planck Institut für molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Malorny
authors.affiliation: Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: Parachuri
authors.initials: P
authors.lastname: Prasad
authors.affiliation: Max Planck Institut für molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Morelli
authors.affiliation: Max Planck Institut für molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany.
authors.forename: Barica
authors.initials: B
authors.lastname: Kusecek
authors.affiliation: Molecular Microbiology Group, University of Southampton Medical School, Southampton General Hospital, Southampton SO9 4XY, UK.
authors.forename: John E
authors.initials: JE
authors.lastname: Heckels
authors.affiliation: Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: Janne G
authors.initials: JG
authors.lastname: Cannon
authors.affiliation: Max Planck Institut für molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Achtman
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D005843:Geography; D006801:Humans; D008302:Mali; D008969:Molecular Sequence Data; D009345:Neisseria meningitidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D011995:Recombination, Genetic; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012703:Serotyping; D014481:United States
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D011994:Recombinant Proteins; C050308:opacity proteins